While the basic technique is sound, SQL recursive queries' no-side-effects character means a huge number of basic graph traversal strategies (e.g.: pruning, sho

While the basic technique is sound, SQL recursive queries' no-side-effects character means a huge number of basic graph traversal strategies (e.g.: pruning, shortest path first/Dijkstra) are beyond reasonable engineering. In addition to that, Postgres is difficult as a computational platform - the execution strategy for recursive queries is not necessarily intuitive, and their performance is hard to assess (for example: how soon will you run out of "stack"?)